mojo4x420

I could use some hints here.

My truck has been driving like crap for a couple of months. I just put in a new air filter, spark plugs, cap/rotor. Did timing, although it seems hard to set my idle right. It's unscrewed more then I ever remember, I hit my brake high rev point a couple times, but truck still idles really low

I have 89 4runner, 22re. Doug Thorley header. One of my header runners cracked on me and was leaking badly. I thought this was hte cause of my problems. I got my header welded back and I reinstalled. I could still hear a small leak when I drove so I tracked down all the gaskets I need and am going to reinstall tomorrow.

My truck was driving bad though. It would really stumble around 2200rpm-2600rpm and then come to life again past that.

This was annoying me so I unplugged my o2 sensor yesterday, thinking I could put it in fail-safe mode. This worked fine for a day. I drove about 100km w/out a single problem. The next day though I had to pull over to the side of the road and suddenly truck was stumbling and it felt like it wasn't going anywhere. I reset my ecu and it instantly drives fine again.

What could be going on? I thought If I unplugged my o2 sensor wire, my truck should stay in fail-safe mode and drive fine like that indefinitely.

Any helps or suggestions appreciated. I've checked probably every sensor in my truck in the past and installed a rebuilt engine less then a year ago.

thanks

mojo4x420

I think there was something blocking coolant flow.

My temp gauge read normal, but eventually I noticed when adjusting my valves that the engine just felt too hot. To the point the rubber on the spark plug wires were starting to feel soft. Bottom rad hose was ice cold and the top hose was almost boiling. It had almost blown off the hose that goes from the thermostat to the idle up valve thing.

My water temp sensor was working, but I suspect when driving it was dumping in gas to prevent me from overheating my engine. My truck's drivability kept getting worse, until it hit the point that as soon as it warmed up, I couldn't drive it.

I replaced my waterpump and coolant and my truck runs mint again. Original waterpump was squeeling at startup, but felt fine when I removed it. Compression is fine, so no damage done, just a few stumped days of poking around.